tbuckley/cabot-search huggingface dataset:
Abstract P1068: Yap Induces A Neonatal Like Pro-renewal Niche In The Adult Heart
Authors: Rich Gang Li, Xiao Li, Francisco Grisanti-Canozo, Yuka Morikawa, Fansen Meng, Jong H Kim, Bing Xie, Elzbieta Klysik, Shijie Liu, Md Abul Hassan Samee, James F Martin
Journal: Circulation Research (2023)

The heart is a poorly renewable organ, meaning that tissue architecture and the cardiac microenvironment are irreversibly disrupted after injury. This presents a major challenge in treatment of ischemic heart disease, the leading cause of death worldwide. To date, most studies have focused on cardiomyocytes (CMs). However, very few studies have examined CM-extrinsic mechanisms, such as innate immunity, that complement CM-intrinsic mechanisms in heart renewal. Inactivation of the Hippo signaling pathway can rebuild the post ischemic microenvironment and improve cardiac function. We investigated spatially resolved cellular relationships of neonatal and adult renewal-competent hearts to gain insight into inefficient mammalian heart renewal. Spatial transcriptomics and single-cell sequencing of adult control hearts and hearts expressing YAP5SA, an active version of the Hippo signaling pathway effector YAP, which models heart renewal, revealed a conserved, renewal-competent CM population in control hearts and amplified in YAP5SA hearts. This CM population was also found in the wildtype, renewal competent neonatal heart after myocardial infarction, as well as the adult human heart. In YAP5SA hearts and neonatal hearts post myocardial infarction, resident macrophages and cardiac fibroblasts expressing complement pathway genes colocalized with these CMs, creating a pro-renewal microenvironment. Complement loss-of-function in fibroblasts or macrophages suppressed cardiomyocyte proliferation in both neonatal injured hearts and adult YAP5SA hearts, indicating that the complement system plays a direct role in heart renewal.
Abstract P2034: Minimally-invasive Porcine Model For The Study Of Cardiac Remodeling In Type 4 Cardiorenal Syndrome
Authors: Spyros A Mavropoulos, Tomoki Sakata, Renata Mazurek, Anjali Ravichandran, Jonas Marx, Nikhil Raisinghani, Susmita Sahoo, Kiyotake Ishikawa
Journal: Circulation Research (2023)

Background: CKD is on the rise, and over half of patients die due to cardiac causes, usually HF. They present with HF not only due to volume overload, but also because of reno-cardiac interactions of unclear mechanisms termed type 4 cardiorenal syndrome (CRS4). In order to understand CRS4, we developed a pig model using minimally-invasive techniques. Methods: 4 female Yorkshire pigs had staged embolization of the renal arteries. Clot/contrast mix was injected by catheter until no flow was seen on angiography. Echo, pressure measurements, angiography, and urine and blood collection to monitor CKD and HF progression was done monthly. At 4 months, GFR and PV loop measurements were also taken, and tissues harvested. Results: BUN (11.3 ± 0.3 vs 5.3 ± 0.5 mg/dL, p &lt; 0.01) and SCr (2.1 ± 0.2 vs 1.3 ±0.1 mg/dL, p&lt;0.01) increased at the endpoint compared to controls, and GFR declined (6 ± 4 vs 124 ± 17 mL/min, p &lt; 0.01). Kidneys showed diffuse fibrosis on trichrome staining. LV mass (136 ± 6 vs 106 ± 6 g, p &lt; 0.05), EDP (16 ± 2 vs 9 ± 2 mmHg, p &lt;0.05), aortic (146 ± 9 vs 96 ± 5 mmHg, p &lt; 0.01) and pulmonary capillary wedge pressures (12 ± 1 vs 6 ± 1 mmHg, p &lt; 0.01) and PA (22 ± 1 vs 16 ± 1 mmHg, p &lt; 0.05) were increased. PV loop showed increased EDPVR slope (0.36 ± 0.03 vs 0.17 ± 0.03, p &lt; 0.01) and Tau (48.9 ± 1.9 vs 36.3 ± 1.1 ms, p &lt; 0.01). LV was fibrotic. Conclusions: Repetitive clot injection successfully induced CKD, seen by increased SCr and BUN, reduced GFR, and renal fibrosis. At 4 months, the heart was hypertrophic, fibrotic, and had PV relationships indicating development of HFpEF. Therefore, we have developed a successful minimally-invasive large animal model of CRS4 for future studies.
Abstract P2156: Endothelium-targeting Exosomes Ameliorate Cardiac Senescence Via Delivery Of Line1 Antisense Oligonucleotides In A Mouse Model Of Myocardial Infarction
Authors: Enze Fu, Yue Liu, Kai Pan, Rongrong Li, Zongjin Li
Journal: Circulation Research (2023)

Transposable elements (TEs), which include long-interspersed element-1 (LINE1) retrotransposon, highly constitute the genome of mammals and their dysregulation is considered the stimulatory factor of genomic damage and innate interferon response and unnatural senescence. The objectives of this study are to determine the functions of LINE1 retrotransposon during myocardial infarction (MI). In this study, selectins, CD62E and CD62P, are identified as the biomarker of the injured endothelial cells in MI. Furthermore, selectin binding peptide (SBP)-engineered extracellular vesicles (SBP-EVs) with targeting functions are developed. We further investigated the SBP-EVs with therapeutic effects by packing LINE1 antisense oligonucleotides (SBP-LINE1-EVs). The results show that SBP-LINE1-EVs exhibit a selective targeting tendency to injured heart with an enhanced myocardium protection effect by LINE1 antisense oligonucleotides delivery. SBP-LINE1-EVs protected against myocardial senescence by inhibiting the reactivation of the innate immune cGAS-STING-TBK1-IRF3 pathway and further repressing the expressions of senescence-associated secretory phenotype (SASP) factors. In conclusion, our findings establish the causal relationship among LINE1, cardiac senescence, and myocardial infarction for the first time. Moreover, we demonstrate the enhanced therapeutic efficacy of the bifunctional SBP-LINE1-EVs system and provide preclinical evidence for targeted therapy of MI by LINE1 inhibition in future clinical applications.
Abstract P3138: Potentiation Mechanism Of SR-Ca2+ Uptake During Myocardial Infarction; A Molecular Explanation Of Ca2+ Arrhythmogenicity Of Purkinje Fibers In The Ischemic Heart.
Authors: Ruhul Amin, Louisa Wiede, Wen Dun, Kazi T Haq, Jules Dore, Henk E Ter Keurs, Penelope A Boyden, Bruno D Stuyvers
Journal: Circulation Research (2023)

Experimental and clinical evidence attributes lethal VTs and VFs associated with ischemic myocardial infarctions ( MI ) to abnormal electric signaling in the Purkinje network. In cardiac Purkinje cells ( Pcells ), spontaneous Ca 2+ releases from the sarcoplasmic reticulum ( SR-CaR ) generate depolarizing Ca 2+ waves which, in turn, can mediate DADs and non-driven APs. Increase of SR-CaR was reported in Pcells of dog heart with 48Hrs MI. An augmentation of SR-Ca 2+ uptake ( SR-CaU ) accelerates SR-Ca 2+ recycling and is a possible cause of larger (pro-arrhythmic) SR-CaR in Pcells of ischemic heart. We tested this hypothesis in canine and porcine models of acute MI.Pcells and heart tissues were prepared 48Hrs after LAD coronary artery ligation. Intracellular Ca 2+ activity was captured by confocal microscopy. SR-CaU was studied by analyzing Purkinje-typical Ca 2+ events, namely Ca 2+ -sparks, peripheral Ca 2+ -wavelets and cell-wide Ca 2+ -waves ( CWW s). Relevance of our analysis was tested with a Purkinje-specific model of Ca 2+ mobilization. Protein/gene expressions of SR-Ca 2+ pump isoforms were studied by immunofluorescence, WBs, and qPCR in dog and pig infarcted tissues.We found that (1) individual Ca 2+ release sites in MI Pcells fired sparks at 61% larger frequency, (2) the duration of wavelet Ca 2+ decay was reduced by 25% due to 37% acceleration of cytosolic Ca 2+ removal (time constant: 156±21ms (Normal; n=10) vs 98±9ms (MI; n=16; P&lt;0.01)), (3) wavelet amplitude was increased by 50%, and (4) larger waves (CWWs) showed similar alterations. Numerical replication of MI wavelets succeeded with 52% increase of Ca 2+ uptake rate in the model of normal wavelets. Our results are consistent with an augmentation of SR-CaU taking place in Pcells shortly after the onset of MI. Molecular analyses done in the same MI model in pig showed that post-MI increase of SR-CaU results from the substitution of cardiac isoform SERCA2a by the ubiquitous and more potent SERCA2b in the infarcted cardiac tissues including Purkinje fibers. Our study reveals, for the first time, the molecular foundation of Purkinje arrhythmogenicity in ischemic heart and highlights novel targets for diagnosis, prevention, and treatment of risk of sudden cardiac death associated with ischemic MIs.
Abstract P2169: Identification Of Pro-adhesive Drugs By A Novel High-throughput Approach
Authors: Pauline Hanns, Ramón Castellanos-Martínez, Volker Spindler, Camilla Schinner
Journal: Circulation Research (2023)

Defective cell-cell adhesion contributes to the patho-mechanism of various diseases. In line with this, a mouse model recently developed by our group demonstrate that loss of cell-cell adhesion is an important initial step leading to Arrhythmogenic Cardiomyopathy (ACM), a disease which presents with severe arrhythmia, ventricular fibrosis and impaired cardiac function. Derived from the central role of defective cell-cell adhesion for the patho-mechanism, we here aim to identify new compounds, which restore intercellular adhesion and could serve as potential therapeutics. To screen a high number of agents, we developed an adhesion-based high-throughput approach by adapting a standard cell-cell dissociation assay to 96-well plate format including establishment of an automated acquisition and analysis pipeline. To model loss of intercellular adhesion, cells deficient for the desmosomal adhesion molecule desmoglein-2 were used. After establishing settings to sensitively detect changes in cell-cell adhesion, this method was applied to screen a library of 1946 FDA-approved drugs in three concentrations. Several new compounds strengthening intercellular adhesion were identified in addition to known pro-adhesive drugs, confirming the robustness of our assay. The increased adhesiveness of selected top hits was confirmed in cells expressing ACM patient mutations. In conclusion, we here developed an adhesion-based high-throughput approach capable of identifying adhesion modulators which have the potential to be used as therapeutics for diseases with defective desmosomal adhesion such as ACM.
Abstract P1181: Targeted Loss Of Sarcolemmal Membrane Associated Protein Isoform 3 (slmap3) In Cardiac Progenitors Stunts The Embryonic Growth Of Myocardium
Authors: Taha Rehmani, Ana Dias, Maysoon Salih, Balwant Tuana
Journal: Circulation Research (2023)

Sarcolemmal membrane associated proteins (SLMAPs) belong to the superfamily of tail anchored membrane proteins known to regulate variety of functions including vesicle transport. SLMAP3 is the largest isoform which is ubiquitously expressed and has been linked to Brugada syndrome and sodium channel activity. SLMAP3 is expressed during cardiogenesis, and we examined its role by nullifying its expression in mouse cardiac progenitors using the Nkx2.5-cre-lox system. Hearts from SLMAP3-knockout (KO) mouse embryos at different stages of cardiogenesis, e9.5, e12.5 and e16.5, were smaller (p&lt;0.05) than wildtype (Wt) littermates. Histological analysis of heart wall measurements from the left ventricles revealed thinner walls in SLMAP3-KO from e9.5 (-25.16%, p&lt;0.05), e12.5 (-29.36%, p&lt;0.05) and e16.5 (-40.27%, p&lt;0.05) compared to Wt although normal chamber formations was observed at these developmental stages. To evaluate the potential reasons for the early difference in cardiac growth, we examined myocardial cell numbers and size with markers of proliferation and hypertrophy. Immunofluorescent analysis of e12.5 hearts with proliferative markers (pH3, Ki67) was not significantly (-5%, p&gt;0.05) altered in KO hearts while cardiomyocyte size differences assessed by immunofluorescence with anti-Troponin C, revealed that KO cardiomyocytes were significantly (-19.4%, p&lt;0.05) smaller than Wt. However, the phospho-to total ratios of AKT1(1.45%, p&gt;0.05) and MTOR1(-12%, p&gt;0.05) were not significantly altered in KO hearts when compared to Wt. SLMAP3 has been implicated in Hippo signaling via the STRIPAK (striatin interacting phosphatase and kinase) complex to impact YAP/TAZ and cell growth. Western blot analysis of e12.5 Wt and KO hearts showed no change in phosphorylation of MST1/2(-6.64%, p&gt;0.05) or YAP-Ser 127(-8.84%, p&gt;0.05) ruling out involvement of Hippo signaling. Interestingly, the expression of the other SLMAP isoforms, SLMAP1 and SLMAP2 remained unaffected during cardiac development in SLMAP3 KO hearts. Thus, SLMAP expression is critical for normal development since the loss of SLMAP3 isoform leads to stunted growth of the embryonic heart. Supported by CIHR.
Abstract P2042: Linking Extracellular Matrix Stiffness With Cardiomyocyte Structure And Function
Authors: Stephanie L Bowers, Tanya Baldwin, Kelly Grimes, Allen York, Michelle Sargent, Yasuhide Kuwabara, Qinghang Meng, Anne Katrine K Johansen, Jeff D Molkentin
Journal: Circulation Research (2023)

The composition and organization of the extracellular matrix (ECM) provides cues to myocardial cells that direct normal function and responses to stress. However, little is known about how exactly a change in environmental tension leads to alterations in cardiomyocyte cell size and contractile force. Collagen I comprises the majority of cardiac ECM where it is crosslinked and matured by the lysyl oxidase (LOX) family of enzymes that includes LOX and LOX-like (LOXL) proteins. LOX and LOXLs are frequently upregulated in the heart after injury, and their inhibition has been shown to alleviate increases in tissue stiffness. Cardiac injury models result in activation and recruitment of many cells that secrete growth factors and modify the ECM, which makes it difficult to address specifically how cardiomyocytes are responding to changes in matrix tension alone. Therefore, we utilized LOX or LOXL overexpression as a tool to stiffen the ECM in the absence of pathophysiologic injury and paracrine factors. Transgenic overexpression of LOX increases myocardial stiffness and results in mild cardiac dysfunction by 9 months of age. While younger adult mice do not display a phenotype at baseline, they have an exaggerated response to pressure overload hypertrophy. In a different set of experiments, adeno-associated viruses (AAV9) for LOXL1, -2, or -3 were administered to mouse pups via cardiac injection at perinatal day 7. By 12 weeks of age, LOXL1 overexpression leads to cardiac hypertrophy with preserved ejection fraction, while increased LOXL2 or LOXL3 results in decreased cardiac function (each with differential patterns of myocardial fibrosis). Ongoing studies are assessing how these functional changes are associated with alterations in tissue stiffness and cardiomyocyte behavior. Determining how cardiomyocytes respond to alterations in the physical properties of the ECM will improve our understanding of the etiology of progressive cardiomyopathies and fibrosis.
Abstract P3018: SCARNA20 Promotes M2 Macrophage Polarization Under Endotoxemia And Reduces Inflammation
Authors: Selene Perales, Vinoth Sigamani, Sheeja Rajasingh, Hemanathan Vembuli, Rahul Pushparaj, Johnson Rajasingh
Journal: Circulation Research (2023)

Background: Macrophage polarization plays a key role in the inflammatory process. M1 pro-inflammatory and M2 anti-inflammatory phenotypes can down-regulate each other and may contribute to the pathogenesis of various diseases. Small Cajal Body Associated RNAs (SCARNAs) play a key role in alternative splicing and maturation of mRNAs. Our recent studies found that a combination of Procainamide (P, DNMT1 inhibitor) and Tubastatin A (T, HDAC6 inhibitor) reduces inflammation upon lipopolysaccharide (LPS) stimuli. Hypothesis: We hypothesize that the P+T treatment increases the expression of SCARNA20 hence reducing the proinflammatory response and promoting M2 macrophage polarization after LPS challenge. Methods and Results: To elucidate SCARNAs of interest during the inflammatory response, we treated macrophages with LPS (1μg/mL) and P (400nM/mL) + T (2.5μM/mL) for 1hr and performed RNA sequencing. Based on the sequencing results and qRT-PCR validation, SCARNA20 was the most significantly differentially expressed SCARNA between conditions (Fig. A) . The expression of TNFα was significantly reduced with the P+T treatment (Fig. B) . SCARNA20 overexpression (OE) showed an increase in the expression of the M2 marker CD163 and a reduction in the expression of the M1 marker CD80 (Fig. C) . Additionally, TNFα expression was significantly reduced in the SCARNA20 OE samples after the LPS challenge without treatment with P+T (Fig. D) . Finally, SCARNA20 knockdown macrophages (Fig. E) treated with P+T did not suppress TNFα expression (Fig. F) . Conclusions: We report for the first time that SCARNA20 is an important regulator of M2 macrophage polarization and pro-inflammatory response.
Abstract P1067: A Perfused <i>In Vitro</i> Model Of Embryonic Heart Tube: Leveraging 3D Bioprinting And Human Induced Pluripotent Stem Cell Technologies To Study Heart Development
Authors: Linqi Jin, Martin L Tomov, Huang Chen, Reza Avazmohammadi, Lakshmi Dasi, Holly Bauser Heaton, Vahid Serpooshan
Journal: Circulation Research (2023)

Human heart development is an intricate dynamic process that remains barely understood, due to the limited access to the developing human heart in utero and the lack of effective modeling systems. Rapid advances in 3D bioprinting and stem cell technologies have enabled the fabrication of cardiovascular tissues with complex structures and microenvironment. Here we present a perfusable model of human embryonic heart tube manufactured using digital light processing (DLP) 3D bioprinting. The bioprinted model contains an endocardium, a cardiac jelly, and a myocardial layer resembling the structure of the human linear heart tube on day 22 ( Figure 1A-D ). Human iPSC-derived cardiomyocytes (hiPSC-CMs) and umbilical vein endothelial cells (HUVECs) were used to cellularize the constructs ( Figure 1F ). Full endothelialization of the heart tube lumen and expression of cardiac troponin T in the myocardial layer were confirmed via immunofluorescent staining ( Figure 1F ). Global tissue contraction in culture demonstrated the viability and cardiac function of the engineered model. Single-cell RNA sequencing further examined the gene expression profiles across different experimental groups. This study establishes the first perfusable model of human embryonic heart tube, which can serve as a robust platform to decipher the complex cellular processes underlying early heart development and the potential impact of microenvironmental factors on these events. Figure 1: A-D: Design of a developing human heart model on embryonic day 22. E-H: The workflow to bioprint ( E ), cellularize ( F ), and conduct dynamic culture ( G-H ) of the embryonic heart models using a perfusion bioreactor system.
Abstract P2032: Wnt5a Mediates Doxorubicin-induced Cardiomyopathy Through Induction Of Senescence
Authors: Eun-Ah Sung, Junichi Sadoshima
Journal: Circulation Research (2023)

Heart failure and cancer are major causes of death in the United States. Doxorubicin (DOX) is a commonly used chemotherapeutic agent. However, its clinical use is restricted due to cardiotoxicity, which can cause cardiomyopathy as well as heart failure. Senescence is defined by irreversible cell cycle arrest, resistance to apoptosis, and a senescence-associated secretory phenotype (SASP). Elimination of senescent cells improves cardiac dysfunction, suggesting that senescent cardiomyocytes (CMs) contribute to impaired heart function. Although DOX-induced senescence has been shown to occur in CMs, little is known about the mechanisms mediating DOX-induced cardiomyopathy. Wnt5a, one of the most studied non-canonical Wnt ligands, has emerged as an important player in cardiac diseases. mRNA expression of Wnt5a is upregulated in induced pluripotent stem cells (iPSC)-derived CMs from patients with end-stage heart failure induced by DOX chemotherapy. However, the role of Wnt5a in mediating the progression of DOX-induced cardiomyopathy remains elusive. We found that Wnt5a protein expression is markedly increased in mouse hearts with DOX-induced cardiomyopathy. Upregulation of Wnt5a following DOX treatment was also observed in neonatal rat CMs (NRCMs), and the degree of upregulation was more prominent in CMs than in non-CMs. We tested whether Wnt5a induces the senescent phenotype in NRCMs. Wnt5a not only induced an increase in p16 protein levels but also increased the number of γH2AX foci per cell and SA-β-gal activity in NRCMs. Wnt5a knockdown markedly reduced DOX-induced increases in p16 protein levels in NRCMs. These results suggest that DOX may induce cardiomyopathy through Wnt5a-mediated induction of CM senescence. Wnt5a may be a novel therapeutic target for the prevention of DOX-induced cardiac dysfunction.
Abstract P3120: Persistent Cardiac Dysfunction In Ovariectomized Independent Of Metabolic Disturbance
Authors: Ahmed Sohail, Adnan A Khan, Elizabeth Russ, Eitezaz Mahmood, Yifan Bu, Feroze Mahmood, Ruma Bose, Kamal R Khabbaz, simon robson, Robina Matyal
Journal: Circulation Research (2023)

Objectives: Postmenopausal women are known to develop metabolic syndrome and cardiovascular disease. We hypothesize that a murine model of ovariectomy (OVX) and high-fat diet (HFD), simulating a post-menopausal milieu, will have decreased activity, changes in body composition, and impaired cardiac activity. Methods: From 5 weeks of age, 11 C57BL/6 mice were fed a HFD and 10 were fed a control diet (CTL). At 12 weeks, 11 mice (5 HFD, 6 CTL) were ovariectomized (OVX). At 30 weeks mice body composition was analyzed with EchoMRI. Metabolic activity was monitored in Promethion metabolic cages for 48 hours. Transthoracic echocardiography (TTE) was performed while mice were anesthetized with 2.5% isoflurane. Results: The OVX mice traveled the furthest distance, and HFD+OVX the shortest distance. HFD+OVX and HFD had increased energy expenditure and higher fat mass compared to CTL (Figure 1). All groups had increased LV Mass, and worse systolic function to control (Table 1). Conclusion: Ovariectomy could be associated in systolic dysfunction independent of development of metabolic syndrome.